Abstract
We report on a study of the evolution of several active regions during
1993 April 17-28 using data
obtained at multiple wavelengths that probe various heights of the
active region corona. We use
simultaneous microwave (1.5 and 17 GHz) and Soft X-ray images obtained
by the Very Large
Array (VLA),
the Nobeyama Radio Heliograph (NRH)
and the Soft X-ray
Telescope (SXT) on
board the Yohkoh spacecraft. We also use photospheric magnetograms from
Kitt Peak National
Observatory to study the development of Solar Active Regions. We have
followed the
development of various observed parameters such as brightness
temperature and polarization
using radio images. The X-ray data were used to track the development of
density and
temperature of active regions. Using the fact that the quiet active
region radiation is thermal and
adopting proper emission mechanism at each frequency domain, we
construct a consistent picture
for the three dimensional structure of the active regions. Particular
attention has been paid to the
mode coupling observed at 17 GHz while the active regions crossed the
solar disk.